Dissipative systems: Implications for geomorphology

A recent revolution in the study of nonlinear dynamical systems in the physical sciences has shown the worth of regarding systems as dissipative. The nature of dissipative systems in equations, bifurcations, and fluctuations. Some speculations are then made concerning the implications of dissipative system theory for geomorphology. It is suggested that geomorphological systems containing bifurcations will have both deterministic (universal and necessary) and probabilistic (historical happenstance) elements; they will have more than one solution (configuration) and this fact calls into question notions of process domains leading to the development of characteristic forms; they will possess varying degrees of susceptibility to change induced by fluctuations; and they will respond differently to local, regional, and global fluctuations.     

金川超镁铁质岩体矿物化学特征及矿物地质温度计、压力计研究

根据金川超镁铁质岩体主要造岩矿物和副矿物的共生组合关系及各种矿物的化学成分特点；选用５种较成熟、使用较方便的矿物地质温度计、压力计（主要是辉石温压计和角闪石压力计），对岩体形成的温、压条件进行了估算，其结果为：成岩温度为１０００～１３００℃（上限可到１４００～１５００℃），成岩压力约为５×１０￣８～１１×１０￣８ｐａ。金川超镁铁质岩体的主要岩石类型为尖晶石二辉橄榄岩，这一岩石类型在复杂体系相关系图中的稳定区域大致处于５×ｌ０￣８～１５×１０￣８ｐａ的范围，这与矿物温压计估算的成岩温压条件是一致的。     

盐湖溶液热化学(Ⅳ) Li_2B_4O_7—Li_2SO_4—LiCl—H_2O体系298.15K时稀释热、热容和表观摩尔热焓的研究

用连续滴定量热法测定了四元体系Li_2B_4O_7—Li_2SO_4—LiCl—H_2O及其次级体系Li_2B_4O_7—Li_2SO_4—H_2O和Li_2B_4O_7—LiCl—H_2O 298.15K时的稀释热,并结合Debye-Hückel热焓极限公式研究了该体系的平均表观摩尔热焓。     

Nonseismic phenomena in the generation and augmentation of tsunamis

While earthquakes generate about 90% of all tsunamis, volcanic activity, landslides, explosions, and other nonseismic phenomena can also result in tsunamis. There have been 53 000 reported deaths as a result of tsunamis generated by landslides and volcanoes. No death tolls are available for many events, but reports indicate that villages, islands, and even entire civilizations have disappeared. Some of the highest tsunami wave heights ever observed were produced by landslides. In the National Geophysical Data Center world-wide tsunami database, there are nearly 200 tsunami events in which nonseismic phenomena played a major role. In this paper, we briefly discuss a variety of nonseismic phenomena that can result in tsunamis. We discuss the magnitude of the disasters that have resulted from such events, and we discuss the potential for reducing such disasters by education and warning systems.     

水系分维的构造含义

本文运用分数维几何学,研究了河流水系分维与地壳里向运动、活动断裂格局及运动学特征的关联性。结果表明:1)地壳垂向运动控制大型河流主干的总体形态;2)活动断裂格局复杂、水平运动强烈的地区,水系分维值高;3)走滑断裂较斜滑断裂对水系发育的控制强烈,而后者主要起到对水系的分区作用。     

Sensitivity of launch systems to gravity field

This paper considers the question of how sensitive inertially guided systems are to variations in the gravity field. There are systems which use other kinds of information for guidance, such as terrain. But, they will not be considered here.     

大陆裂谷盆地层序地层学的研究

本文以松辽裂谷盆地为例，讨论了层序地层学在陆相湖泊盆地中的应用实例，提出了适用于内陆湖泊盆地的层序地层学的术语和模式。根据大陆裂谷盆地的演化阶段特征，划分为同裂谷沉降超层序和后裂谷沉降超层序，指出两个超层序在形成机制和组份上的差异，并相应建立了两类层序地展模式；根据古湖泊发展过程中出现枯水湖—丰水期—枯水期的周期性演化特点，划分为湖进体系域、湖泛体系域和湖退体系域。     

K-Ar dating of ring complexes and fault systems in Northern Kordofan,Sudan: evidence for independent magmatic and tectonic activity

From an area of brittle shearing and ring complexes in Northern Kordofan, Sudan 28 K-Ar ages were calculated to determine the geochronology of tectonic and magmatic events. The age results for deformational episodes are 560, 340 and 255 Ma, whereas alkaline magma was intruded at 280, 220 and 165 Ma. The incompatibility of age marks leads to the conclusion that magmatic and tectonic activity in this area have to be regarded as independent events. This holds true even when all dated intrusions from the entire region are compared with post-Pan-African continental tectonic features.     

Telecommunications and the Large City-Small City Divide: Evidence from Indiana Cities*

Urban systems are increasingly dominated by large cities that house a disproportionate share of telecommunications infrastructure. This paper investigates whether telecommunications is defining a technological divide between large and smaller cities. The paper provides a conceptual basis for large-city dominance and presents the results of surveys that investigate the use of telecommunications in medium and small Indiana cities. The survey data indicate that telecommunications is used by the set of Indiana cities, but is less prevalent among the set of smallest cities. Chi-square tests, however, suggest that city size does not adequately explain these variations in use.